Emergency services are responding to an explosion at the headquarters of oil company Pemex in Mexico City. Officials say 14 people died and 100 were injured in the blast at the tower block. It is not yet clear what caused the explosion.

An explosion has rocked the ground floor of the Mexico City headquarters of state oil company Pemex, killing one and injury many others, according to local media.

The building is understood to have been evacuated did it is not yet clear what caused the explosion.

Mexican television images showed debris scattered near the base of the skyscraper and injured people being taken out on stretchers.Local media are reporting 22 people had been injured in the explosion and that one person had died in the building.

Plaster had fallen from the ceiling of the basement, and the situation at the Pemex tower was "delicate," a spokesman for local emergency services said.